Page 1 of 1

Gti eng overheating

Posted: Mon Nov 27, 2006 5:30 pm
by beaver700
Gday,

I took my 'gti sierra' for a drive today.

It was pretty sweet, except I noticed that the engine was overheating a fair bit... also during the engine swap, the stock temp gauge on the instrument cluster has ceased to work...

1. I used the standard sierra radiator, which was cracked open and cleaned out a month before.
2. I am using a big electric fan which covers the entire radiator. It is mounted on the engine side of the radiator.
3. The system was bled out of air while idling.
4. Thermostat seemed to be working okay.
5. Fresh quality coolant in system (70ml to l litre water)
6. When felt the hose coming from the thermostat was way to hot to touch
7. The hose from the bottom of the radiator - I could put my hand on it without getting burnt.
8. It seems to maintain a ideal temp while idling... but overheats on driving about 50km's/hr



Any help as to why it is overheating would be good... I dont really want to put in a bigger radiator because I want to fix the problem and not just use a band aid fix... :?


Thanks,
Martin

Posted: Mon Nov 27, 2006 7:10 pm
by Santos
water pump failure?

Posted: Tue Nov 28, 2006 8:54 am
by noelb1
pull your thermostat out and run the car see if it does it , is there any flow through the radiator??

Re: Gti eng overheating

Posted: Tue Nov 28, 2006 9:27 am
by noelb1
beaver700 wrote:Gday,

I took my 'gti sierra' for a drive today.

It was pretty sweet, except I noticed that the engine was overheating a fair bit... also during the engine swap, the stock temp gauge on the instrument cluster has ceased to work...

Thanks,
Martin
check the temp sender

Posted: Tue Nov 28, 2006 10:32 am
by Guy
Is the thermo fan wired up properly ? (ie set to suck not blow, simple and suprisingly common mistake).

Posted: Tue Nov 28, 2006 12:56 pm
by beaver700
Thanks guys, :D

I will check all the above.

Cheers

Posted: Wed Nov 29, 2006 11:08 pm
by mr green
sounds like you have got no flow. my guess is blocked radiator again. they work great as a filter, catching all the crap from the motor you just put in. i went through the same deal

Posted: Thu Nov 30, 2006 8:05 pm
by beaver700
Gday,

As far as I knew, the water pump was working alright when I put it in. As for checking flow, all I have done so far is squeeze the top radiator hose, but it was too hot to touch for too long, so I pulled it off at the radiator, and coolant started to pour out...
Is there a better way to check flow?

I think I might pull the radiator out and reverse flush it...


If anyone has any more suggestions, they would be welcome :armsup:

Thanks,
Martin

Posted: Thu Nov 30, 2006 8:06 pm
by Guy
did you check the other stuff mentioned ??

Posted: Thu Nov 30, 2006 9:47 pm
by beaver700
Does anyone know a test to find what is the matter with the temp gauge?

I can see a white/yellow wire in the engine bay which was connected to the old sierra temp sender, when I plugged it in the gti sender, it never seemed to register....

Ive checked the thermo fan, it is set to blow.

The thermostat seems okay, but I havent got around to running the engine without it...

It seems the first thing I need to do is fix the current temp gauge (?) or buy aftermarket (which I really dont want to do).


Thanks in advance
Martin

Posted: Fri Dec 01, 2006 7:16 am
by noelb1
you will need a multi meter and the service manual that has what ohms/volts( cant remember which one , the service manual will tell you) it is suppose to read when hot and cold.

Posted: Fri Dec 01, 2006 7:37 am
by noelb1
if you haven't got a manual pm me I will email pages.

Posted: Fri Dec 01, 2006 7:54 am
by 84ZOOKSTA
beaver700 wrote:
Ive checked the thermo fan, it is set to blow.
When you say BLOW is that blowing air through your radiator from your engine bay????

If it is it should be drawing air through your radiator from the front of the radiator and blowing it over your engine.


Cheers

Posted: Fri Dec 01, 2006 10:03 am
by beaver700
Gday,

Thanks for all the advice provided...


84ZOOKSTA: The thermofan is blowing air out the front of he radiator... I had a feeling that it should be the other way around i.e drawing air through the radiator onto the engine...will fix up thanks :)

noelb1: Thanks, I have got a manual, and will check the page which mentions the temp info.


Please excuse another dumb question: In theory the lower radiator hose should be significantly a lower temperature than the upper one coming from the thermostat? After the car has been warmed up, wwould it be possible to put my hand on it without burning?. In other words, how hot should the lower radiator hose be after the car should be warmed up?

I know its a really stupid question, :?

Thanks

Posted: Fri Dec 01, 2006 11:25 am
by 84ZOOKSTA
The temp of the bottom hose is not something that can NOT be calculated, There are so many varables, eg air temp, air flow, radiator size and efficency, water pump flow etc that determine what temp the bottom hoser would be.

You could do a test by running the car up to temp with the radiator fan disconnected and chech the temps on both the top hose and the bottom hose, Then repeat the process with the fan running and see what the difference is but that is is only going to be an indication of how efficent the fan is and how well your radiator is working.

Cheers
Simon..

Posted: Fri Dec 01, 2006 11:27 am
by noelb1
if all is working well it should beable to de touched with out too much hassle

Posted: Fri Dec 01, 2006 11:36 am
by Guy
beaver700 wrote:Gday,

Thanks for all the advice provided...


84ZOOKSTA: The thermofan is blowing air out the front of he radiator... I had a feeling that it should be the other way around i.e drawing air through the radiator onto the engine...will fix up thanks :)
There is your problem ... take it for a spin, I bet it no longer overheats.

Posted: Fri Dec 01, 2006 11:01 pm
by mr green
to test flow through your radiator, take top and bottom hoses off, stick your garden hose in the radiator cap hole and turn the tap on flat out. you should not get any water running out of the top hose outlet. if you do you will have to get the tank pulled out to clean the core. but i hope the fan fixes it.

Posted: Tue Dec 12, 2006 2:29 pm
by chuckwilltalk
gday mate im just wondering how difficult it was to do with the gti conversion as ive been thinkin of this but have been told its very hard, also what sort of top speed does it giv your suzi with the swift motor in it? cheers